1. Field of the Invention
The present invention relates to a test handler, and more particularly, to a pusher for a match plate of a test handler that supports a tester to test the produced semiconductor devices.
2. Description of the Related Art
A test handler is a piece of equipment that loads semiconductor devices manufactured by a certain process onto a test tray, supports a tester to test the semiconductor devices loaded onto the test tray, sorts the semiconductor devices according to the test result, and then unloads the semiconductor devices from the test tray onto customer trays. Technology related to the test handler has been disclosed through many publications, such as Korean Patent No. 10-0553992 (hereinafter, referred to as prior art).
In general, the produced semiconductor devices are loaded onto customer trays and then transferred to the test handler. The semiconductor devices are loaded from a customer tray onto a test tray located at a loading site. The semiconductor devices loaded onto the test tray are moved via a test site to an unloading site and then unloaded onto a customer tray.
While the semiconductor devices are moving within the test handler, they are tested at the test site by a tester docked to the test handler. Specifically, a pushing apparatus pushes the semiconductor devices placed on inserts of the test tray to test sockets of the tester. The conventional pushing apparatus includes: a match plate for matching with a test tray; and a cylinder-piston unit for pushing and pulling the match plate toward and from the test tray. The match plate is configured in such a way that a plurality of pushers is coupled in an installation plate, in a matrix. The pushers correspond to the inserts of the test tray, one by one. The pushers serve to push the semiconductor devices placed on the inserts to the test sockets of the tester, so that the semiconductor devices can be contacted with the test sockets.
Since the semiconductor devices are used in various environments, they are tested under poor temperature conditions prepared in the test handler. To this end, the conventional test method just supplies air (cool- or heated-) to the test site so as to maintain the semiconductor devices located at the test site at the required temperature. However, the temperature of the semiconductor devices, close to the air supplying apparatus, differs from that of the semiconductor devices, far from the air supplying apparatus. That is, because the semiconductor devices close to the air supplying apparatus maintain around the temperature of the supplied air, but the semiconductor devices far from the air supplying apparatus contact the supplied air through convection. Therefore, the conventional test method has a disadvantage in that all the semiconductor devices placed on the test tray located at the test site cannot be under the same temperature conditions, thus deteriorating test reliability. That is, the conventional test method causes temperature deviation among semiconductor devices at the same test site, so that they are tested in different test conditions. Of course, it is natural that the semiconductor devices at the same test site are subject to undergo some of temperature deviation, however, it should be noted that as the temperature deviation increases, the test results becomes less reliable.
In order to resolve such a problem, as disclosed in the prior art, the present applicant of this application has developed a technique where air can be supplied individually to the respective semiconductor devices placed on a test tray. As disclosed in the prior art, the prior test method allows air to be directly supplied from the duct to the semiconductor devices, and thus can maintain all semiconductor devices located at the test site within the temperature deviation of 2° C., unlike the conventional method that uses the air convection principle.
The ideal test condition is when all of the semiconductor devices are subject to the same temperature at the test site. To this end, techniques must be developed to reduce any temperature deviations among semiconductor devices at the test site.
When the number of semiconductor devices to be tested at one time (once) is increased, temperature deviation among the semiconductor devices is probably increased. This is due to the fact that the semiconductor devices to be tested are subject to the thermal state of the ambient air temperature thereof. Specifically, the ambient air of the semiconductor devices placed in the center portion of the test site is hardly affected by the outside air, but the ambient air of the semiconductor devices placed in the outer portion of the test site is affected by the outside air. Therefore, if the number of semiconductor devices to be tested once is increased, the temperature deviation increases in proportion to the distance between the semiconductor devices in the center portion of the test site and the semiconductor devices in the outer portion.
It is preferable that air is supplied to the respective semiconductor devices and, at the same time, to the test site so that the environment surrounding the semiconductor devices can be maintained under a proper temperature state during the test.
As described above, the math plate is configured to include an installation plate and a plurality of pushers installed to the installation plate in a matrix.
Referring to FIG. 1, each pusher 100 includes: a body part 110; and a pushing part 120 that extends forward from the front side of the body part 110, for pushing a semiconductor device (D) placed on an insert of a test tray. The pusher 100 forms an air through hole 130 through which air can be supplied to the semiconductor device. The air through hole 130 extends through from the rear side of the body part 110 to the front side of the pushing part 120, and allows air supplied from a duct (not shown) to flow to the semiconductor device (D), as illustrated by an arrow. As shown in FIG. 2, the front side of the pushing part 120 forms a cross-shaped groove 140 crossing the air through hole 130 and the cross-shaped groove 140 serves to provide a channel that allows air supplied to the semiconductor device (D) to flow out.
However, the prior art has a problem in that the amount of air supplied to the air through hole 130 is relatively small when considering the ambient air temperature of the semiconductor device (D).
To resolve this problem, if the air through hole 130 is increased in its diameter to allow a larger amount of air to be supplied, one semiconductor device (D) is subject to different pressures among its center portion (i.e., near the air through hole), a portion near the cross-shaped groove 140, and the outer portions of the semiconductor device (D). In that case, the semiconductor device (D) may be damaged. Consequently, there is limitation to increase the diameter of the air through hole 130. Similarly, it also causes that the width increment of the cross-shaped groove 140 must be limited.
As shown in FIG. 3, according to the prior art, since the insert (I) closely connects its sectional portion C to the pusher 100, the air passing through the air through hole 130 must be compulsorily discharged through the gap between the parts of the insert I. Although a large amount of air is supplied, at a high pressure, to the air through hole 130 from the duct, the channel is not sufficiently secured to allow the high pressure air to flow out, which causes that sufficient air cannot be supplied to the test site. Furthermore, there exists a high probability of damage occurring to parts of the insert while the high pressure air is flowing out through the gaps between the parts.